This Continuation proposal is based on interim findings from a NIAAA-funded study to evaluate a community-based alternative transportation program to prevent Driving While Intoxicated (DWI). These findings show that drinkers who use designated drivers (DDs), who serve as DDs, or who use safe rides (SRs-free taxi rides home for intoxicated drivers) are more likely than other drinkers to report DWI and riding with intoxicated drivers (RID). They are also more likely, however, to engage in behaviors to avoid DWI and RID, such as waiting to drive until the effects of alcohol diminish, walking home, and staying overnight (Caudill & Harding, 1997; Caudill et al., 2000a; 2000b; in press). Subsequent studies similarly revealed that heavy drinkers were either more likely or as likely as moderate drinkers, and more likely than light drinkers, to report DWI and RU) and high levels of DWI and RID (Caudill et al., 1999; 2000c). Heavy drinkers were also more or as likely as moderate, and more likely than light drinkers, to report behaviors to avoid both DWI and RID and to report high frequencies of these avoidance behaviors. Heavy drinkers also exhibited DWI risk avoidance behavior, relative to DWI risk behavior, just as often as moderate or light drinkers, namely 70 percent versus 72 percent, and 72 percent of the time they drink to intoxication outside the home (Caudill et al., 2000c). Recent analyses show that drinkers who report DWI are more likely than drinkers who do not, to engage in behaviors to avoid DWI and RID, including the use of DDs and SRs. The main goal for the proposed study is to learn why at-risk drinkers engage in DWI on some occasions, but avoid DWI on others. A secondary goal is to learn why drinkers engage in RID on some occasions but not others (RID can be examined efficiently since 67 percent of those reporting DWI in our current study also report RID). Most research on risk-taking compares individuals who exhibit the behavior with those who do not. Because of the difficulty of controlling for many potential differences between such subjects, we propose a design that compares occasions when the same at-risk drinkers exhibit risk with occasions when they do not. A representative sample of 800 barroom drinkers who report both DWI and avoiding DWI will participate in a CATI interview designed to collect detailed data about the last occasion (during the past two weeks) when they drove while feeling intoxicated, and last occasion when they avoided DWI. Using this self-matched case control approach, analyses will identify situational (e.g., type of drinking companion), motivational (e.g., fear of arrest), and other variables (e.g., Blood Alcohol Concentration, gender) associated with these two choices. Findings will be used to identify prevention strategies that might either reinforce the use of alternatives to avoid DWI and RID, or reduce identified barriers to their use. A panel of national experts will be used to help refine the study design and tie findings to the development of future innovations in DWI and RID prevention.